Quality control nondestructive tests

The most important factor is that the tests relate to service conditions and to aspects of product performance. The tests should not be too complex, although rapidity and cheapness are less important than was the case with quality control. Nondestructive tests are not always appropriate when predicting product performance, as it may be necessary to establish the point at which failure occurs. 

Hardness is used in identification, classification, and quality control. Hardness tests provide a rapid evaluation of variations in mechanical properties affected by changes in chemical or processing conditions, heat treatment, microstructure, and aging. Since the hardness test usually produces an insignificant permanent change in the specimen, it is considered to be a nondestructive test. 

The basic condition of the Standard application - the availability of stable coupled probabilistic or the multiple probabilistic relations between then controlled quality indexes and magnetic characteristics of steel. All the probabilistic estimates, used in the Standard, are applied at confidence level not less than 0,95. General requirements to the means of control and procedure of its performance are also stipulated. Engineers of standard development endeavoured take into consideration the existed practice of technical control performance and test at the enterprises that is why the preparation of object control for the performance of nondestructive test can be done during the process of ordinary acceptance test. It is suggested that every enterprise is operated in correspondence with direct and non-destructive tests, obtained exactly at it, for detailed process chart and definite product type, however the tests have long since been performed after development of the Standard displayed that process gives way to unification. 

This Chapter includes the requirements for inspections by owner, quality control examinations, nondestructive examinations, and specified tests by the construction organization (manufacturer, fabricator, or erector). Inspection, examination, and testing shall be in compliance with the general requirements of Chapters GR-4 and GR-6, as well as the applicable specific requirements in this Chapter and engineering design. 

The modulus of elasticity (MOE) is related to the strength and can be used as a nondestructive quality control test on high cost special refractory shapes such as slide gate valves employed in the pouring of steel (qv). The slide gate type must be selected to ensure chemical compatibility and it must be used in a way to reduce thermal shock. The performance of a properly selected and used slide gate is direcdy related to its strength and therefore predicted by its MOE. 

In many pharmaceutical companies, quality control departments already use NIRS to identify formulations. Figure 23 illustrates a PLS calibration for the active content determination in a low-dose tablet. Once identity testing is passed, it is straightforward to consider as a next step the determination of active content in intact tablets. Thus, qualitative and quantitative analysis can be performed by acquiring a single NIR spectrum per sample. Two analytical techniques are replaced by one—nondestructive—NIR measurement. For this purpose near-infrared spectroscopy is a fast and powerful alternative to traditional analysis, which only remains necessary as reference analytics. 

The modulus of elasticity (MOE) is related to the strength and can be used as a nondestructive quality control test on high cost special refractory shapes. 

Visual, Nondestructive QC Testing of Joints. There are several forms of nondestructive testing (NDT) that can be used to determine the quality of the final joint. Those that are most appropriate for on-line quality control are described immediately below. More sophisticated nondestructive testing processes are described in the Chap. 20. 

There are several ways that actual joints can be tested. For quality control purposes, a proof test is commonly used, as described above. This test imposes a stress on the specimen but limits it to a point well below where any destruction of the joint can occur. This type of test only looks for serious flaws in the bonding processes such as interface contamination, air entrapment in the joint, or undercured adhesive. The prototype joints can also be tested to destruction by using similar test methods described above for standardized testing. This, however, is generally not done at great frequency because of the cost. Generally, most actual joint tests are performed to ascertain the cause of failure (i.e., forensic analysis of the failed joint) or for nondestructive determination of the adequacy of the bond. 

Nondestructive Testing. Nondestructive testing (NDT) is far more economical than destructive test methods, and every assembly can be tested if desired. Several nondestructive test methods are used to check the appearance and quality of structures made with adhesives or sealants. The main methods are simple ones such as visual inspection, tap, proof, and more advanced physical monitoring such as ultrasonic or radiographic inspection. The most difficult defects to find are those related to improper curing and surface treatments. Therefore, great care and control must be exercised in surface preparation procedures and shop cleanliness. 

Quality control of BDD electrodes is essential and is performed both by nondestructive and destructive testing methods. Nondestructive methods are either routine methods performed on each electrode (Raman spectroscopy to evaluate sp3/sp2... 

The nondestructive test required by API 5L paragraph 9.1 (a) shall be performed for final acceptance after expansion and hydrostatic testing. Any nondestructive examinations performed prior to. this shall be for the mills internal quality control and subject to the buyers mill representative s review. 

Hardness of a material may be determined in several ways (1) resistance to indentation, (2) rebound efficiency, and (3) resistance to scratching. The first method is the most commonly used technique for plastics. Numerous test methods are available for measuring the resistance of a material to indentation, but they differ only in detail. Basically they all use the size of an indent produced by a hardened steel or diamond indentor in the material as an indication of its hardness—the smaller the indent produced, the harder the material, and so the greater the hardness number. Hardness tests are simple, quick, and nondestructive, which account for their wide use for quality control purposes. 

Prior to, during, and after fabrication of the reactor vessel, nondestructive tests based upon Section III of the ASME Boiler and Pressure Vessel Code are performed on all welds and forgings as indicated. The nondestructive examination requirements including calibration methods, instrumentation, sensitivity, reproducibility of data, and acceptance standards are in accordance with requirements of the ASME B PV Code, Section III. (See Table 5.2-1). These methods, procedures and requirements are compatible with Section XI of the ASME Code so that results of preservice inspections can be correlated with in-service inspections. Strict quality control is maintained in critical areas such as calibration of test instruments. 

Smart Structural Technology for Nondestructive Evaluation of Concrete. Identifies two specific applications for use of tagged particles in construction materials for long-term condition assessment and quality control. These particles were tested in asphalt and Portland cement concrete mixes. 43 pages. SHRP-lD/UFR-92-608... 

Next, all materials are weighed. The computer prints an outweigh verification report that confirms that the order is correct, and this becomes part of the permanent batch record. The first analytical check begins as soon as raw materials are received on the dock. To confirm the material is what it claims to be, a quality control (QC) technician performs nondestructive FTNIR spectroscopy. A special stainless steel probe is inserted into each sample. If the test fails, the material is quarantined and further analyzed in the lab. In addition, the QC technician pnUs samples based on the square root of the number received minus one. For example, in a shipment of nine drnms, the technician puUs four samples. After confirmation of identity, materials are pnt on hold and stored in the warehouse. When quality assurance is satisfied with the results of its test, the material is released for processing. 

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